Courtesy: u-blox
The Web of Issues (IoT) ecosystem as we speak
The IoT ecosystem is experiencing a revolutionary part. Most Cellular Community Operators (MNOs) have introduced and even executed the switch-off of legacy 2G and 3G mobile applied sciences, migrating the associated frequencies to 4G or 5G networks. In consequence, IoT builders should additionally undertake a brand new mobile commonplace.
Though 5G is already beneath deployment, its use faces a number of challenges. Moreover limitations in international protection, present 5G options don’t meet most IoT necessities: excessive energy consumption, value, measurement, and design complexity are a number of the drawbacks. 5G RedCap and MMTC are anticipated to handle these points sooner or later. For now, 4G LTE is the one mobile expertise that gives ubiquitous international protection and may play this position for no less than the following 5 years.
A bipolar panorama
In 2016, 3GPP Rel 13 specified new 4G mobile requirements for the IoT. The intention was to compete with non-cellular Low Energy Extensive Space (LPWA) applied sciences, like SigFox or LoRaWAN. The brand new mobile requirements that 3GPP launched had been NB-IoT (aka LTE Cat-NB), LTE-M (aka LTE Cat-M), and LTE Cat 1bis (3GPP Rel 8 had already specified the LTE Cat 1 commonplace).
Following 3GPP Rel 13, MNOs and chip producers centered on NB-IoT and LTE-M, leaving apart LTE Cat 1bis. This determination was made as a result of, evaluating specs, the Cat 1bis professionals/cons ratio was much less beneficial than the opposite two.
An intense debate arose across the new proposed mobile LPWA applied sciences for the IoT. One facet pushed towards utilizing NB-IoT, whereas the opposite towards LTE-M as up to now, nations might independently agree on deployed expertise, supported bands, and roaming agreements.
However other than a couple of exceptions like IMT-2000’s early rollout in Japan or the preliminary deployment of CDMA/EV-DO in North America earlier than converging to UMTS/HSPA, the world was beneath international convergence.
Extra just lately, that convergence was not noted of the image. APAC and most of EMEA selected NB-IoT implementations, whereas the Americas, Japan, South Korea, and Australia selected LTE-M.
The divergence created a bipolar world. China pushed onerous for NB-IoT; certainly, China is the one nation the place NB-IoT has had an enormous deployment. North America, however, deployed LTE-M rapidly. Right this moment, LTE-M dominates most of this market, though some MNOs have added NB-IoT help through the years. EMEA’s case is peculiar. Initially, it opted for NB-IoT. Later, nevertheless, most MNOs in Western European nations additionally added LTE-M help.
Whereas LTE-M traits match most IoT necessities, this isn’t true for NB-IoT. Even when NB-IoT has higher MCL (Most Coupling Loss) than LTE-M, its information price is proscribed. As well as, the design of NB-IoT infrastructure doesn’t help mobility (handover) and voice.
Within the present situation, we discover areas the place IoT functions profit from glorious LTE-M protection (like North America), whereas in others, it’s partially or fully absent. When the latter state of affairs occurs, NB-IoT can’t fulfill most use instances because of the abovementioned limitations.
In Europe, many IoT functions nonetheless connect with legacy 2G (the place out there). Prospects ask for LPWA modules with 2G fallback as a result of LTE-M protection is unreliable and, in worst instances, absent. NB-IoT capabilities don’t fulfill use case calls for.
Till just lately, LTE Cat 1 was the lowest-cost 4G mobile expertise with international protection. A disadvantage of LTE Cat 1 is that its chipsets value way more than these for NB-IoT or LTE-M. Furthermore, an LTE Cat 1 design is extra complicated and requires further parts in comparison with LTE-M and NB-IoT, which considerably impacts the general value.
This case has led IoT builders and MNOs to seek for cost-effective options and thus assure LPWA worldwide connectivity, mobility, and roaming for the IoT ecosystem — leading to a renewed curiosity in LTE Cat 1bis.
What’s Cat 1bis?
In a nutshell, LTE Cat 1bis is LTE Cat 1 with a single obtain (Rx) antenna. All the opposite gadget traits, like uplink (UL) / downlink (DL) information charges and protocols, stay the identical. Quite the opposite, commonplace LTE Cat 1 (3GPP Rel 8) helps Rx range and requires two Rx paths.
Rx range improves RF reception capabilities, particularly on the fringe of the cell. However to help Rx range, the LTE Cat 1 chipsets require two RF inputs with a complicated RF front-end and particular software program. To some extent, this is the reason LTE Cat 1 chipsets value greater than these for LTE-M and NB-IoT, and why LTE Cat 1 functions require extra elaborated and intensive PCBs, further parts, and two antennas. All these options end in larger prices: an LTE Cat 1 answer might value twice as a lot as its LTE-M counterpart.
Eradicating the Rx range characteristic from the LTE Cat 1bis commonplace allows easier, cost-optimized chipset designs. Builders are benefiting from this to design easier, smaller, and cheaper IoT functions than they might with the LTE Cat 1 commonplace.
Why think about LTE Cat 1bis as a further choice for LPWA?
- Evaluating LTE-M and LTE Cat 1bis, each will be appropriate expertise selections for IoT functions, relying on the area and use case. There are a number of causes for this:
- Energy consumption: Each LTE-M and LTE Cat 1bis help low-power modes like PSM and eDRX. These prolong battery life, an vital characteristic for a lot of IoT functions.
- Complete answer value: Each LTE-M and LTE Cat 1bis can value half as a lot as an equal answer primarily based on LTE Cat 1, representing important financial savings.
- 5G compatibility: LTE Cat 1bis is a 4G community expertise that connects to the 4G Developed Packet Core (EPC). In concept, LTE-M and NB-IoT requirements can connect with the 5G core. But, MNOs haven’t applied this performance, and none have introduced plans to take action.
- Information price/latency: LTE Cat 1bis outperforms LTE-M by way of latency and information price, matching the capabilities of LTE Cat 1 with as much as 10 Mb/s downlink and 5 MB/s uplink. This typically exceeds the necessities of IoT functions. LTE-M has a downlink restrict of 375 kb/s and an uplink restrict of 1 Mb/s.
To summarize, each LTE Cat 1bis and LTE-M meet the necessities of most IoT use instances beforehand served by 2G and 3G applied sciences: medium bandwidth, low energy consumption, and low value, amongst others.
Why think about LTE Cat 1bis as an LPWA different now? What driving elements could lead on IoT builders to ponder LTE Cat 1bis as an LPWA choice? We should think about the precise use case, value hole, and standing of LPWA international deployments to reply these questions. When selecting the best communication expertise, 4 concerns are at stake. The next is a quick however on no account exhaustive listing:
- The quantity of transmitted information and the impression on the battery
- Community protection and availability
- Service lifespan
- Hyperlink price range
- Gadget measurement
The quantity of transmitted information and the impression on the battery
We should think about that IoT functions like video surveillance, alarm techniques with video, or eHealth, produce appreciable information quantity. These use instances might leverage LTE Cat 1bis operators with 20 MHz bandwidth in comparison with 1.4 MHz for LTE-M.
With extra bandwidth, units can transmit information sooner. This interprets into much less time within the air and, consequently, much less battery utilization. Relying on the quantity of knowledge, sooner transmission means much less time within the air, leading to higher energy effectivity.
Community protection
The worldwide portability supplied by legacy 2G and 3G applied sciences is ending because of the sundown of mobile requirements in lots of nations. LPWA applied sciences reminiscent of LTE-M and NB-IoT have been deployed with out a lot coordination, making a peculiar international state of affairs. APAC and most Japanese European nations have solely NB-IoT protection, whereas the Americas, Australia, and some European nations have each NB-IoT and LTE-M. Though on this latter case, the protection faces a number of obstacles.4G LTE is current in most African nations the place neither NB-IoT nor LTE-M has been deployed. The exception to the rule is South Africa, the place NB-IoT is at present energetic.
Roaming agreements must also be thought of. They’re scarce, and there’s no assure that an IoT gadget touring between nations could have community entry, even when there may be adequate protection in each areas.
Contemplate Italy for example, though this is applicable to different Western European nations as effectively. Italian MNOs, like most European MNOs, initially deployed NB-IoT. However in current instances, Vodafone Italy added LTE-M help (2022). This doesn’t essentially imply that LTE-M is on the market in every single place, particularly contemplating that the NB-IoT protection is just not complete. So even when LTE-M is on the market, the Italian territory lacks full protection with no certainty when this will likely be achieved.
One other instance is the US, the place LTE-M has been extensively deployed with good protection throughout many of the nation, leading to a big put in base of LTE-M IoT units. But, NB-IoT has been much less prioritized. Though US MNOs have deployed NB-IoT networks, the put in base is far smaller in comparison with LTE-M.
LTE Cat 1bis is on the market wherever there’s a 4G LTE community, which is the case in most populated components of the world. Roaming between 4G networks is essentially potential beneath current agreements, making LTE Cat 1bis significantly appropriate for cell functions reminiscent of telematics and asset monitoring. Examples like this might encourage IoT builders to think about LTE Cat 1bis as a viable LPWA choice.
Service lifespan
Presently, it’s troublesome to say which expertise, LTE Cat 1bis or LTE-M, could have an extended lifespan. The MNOs haven’t introduced any sundown plans for both expertise, and the timing is more likely to differ from area to area.
Some markets, like the US and a few APAC nations, could transition to 5G extra rapidly. This might incentivize community operators to shift from the present 4G spectrum to 5G. Elements to think about could embrace the variety of legacy units on their networks, the bandwidth every expertise consumes, and which bands will likely be prioritized for the transition. Different markets, nevertheless, will transfer way more slowly and should maintain each applied sciences alive effectively into the late 2030s.
Hyperlink price range
LTE-M has a Most Coupling Loss (MCL) of -154 dBm in comparison with -149 dBm for LTE Cat 1. LTE Cat 1bis experiences a further 3-4 dB loss in comparison with Cat 1 because of the absence of the Rx range antenna. Which means the MCL of LTE Cat 1bis is 8-9 dBm worse than LTE-M. The upper MCL of LTE-M ensures higher connectivity in difficult sign circumstances, reminiscent of harsh city environments, garages, or on the cell edge. Nevertheless, LTE-M’s deeper sign penetration is partially offset by its decrease cell density in comparison with commonplace 4G LTE.
Gadget measurement
Builders discover it onerous to handle some use instances, even contemplating the present miniaturization of digital parts. LTE Cat 1 ticks many containers to be used instances like wearables that require small measurement and medium information charges, providing benefits by way of bandwidth, protection, and energy consumption. Nonetheless, miniaturization has been difficult because of the want for a dual-antenna design.
The truth that designers intention for small options forces them to seek out the equilibrium between efficiency and measurement. Consequently, many present small type issue LTE Cat 1 designs omit Rx Range and don’t embrace a second antenna.
With its simplified antenna, shorter components listing, and extra affordability (in comparison with LTE Cat 1), LTE Cat 1bis can even exchange LTE Cat 1 in lots of use instances.
Conclusion
Each LTE Cat 1bis and LTE-M are appropriate expertise selections for LPWA functions. So earlier than making a alternative, one should think about expertise traits and regional deployment. One could also be a greater candidate than the opposite, or perhaps each might be thought of. u-blox can help with this sort of choice, relying on particular use instances and MNOs.
u-blox provides a broad portfolio, together with LTE-M, LTE Cat 1, and LTE Cat 1bis modules. u-blox established early market management in LTE-M with the primary licensed LTE-M module collection, SARA-R4, which additionally provides 2G fallback. u-blox additionally developed its personal LTE-M chipset, the UBX-R5, which was used as the idea for the u-blox SARA-R5 module collection. Each collection have been additional miniaturized into the LEXI-R4 and LEXI-R5 type elements.
For LTE Cat 1bis, u-blox provides the LENA-R8 and LEXI-R10 collection. LENA-R8 can also be out there as a combo: LTE Cat 1bis + GNSS variant. The GNSS core is the brand new u-blox M10 GNSS platform. The LENA-R8 combo (LENA-R8M10) has two energy provides, offering prospects with glorious energy administration flexibility, thus optimizing the general efficiency. LEXI-R10 is the world’s smallest LTE Cat 1bis module supporting Wi-Fi scanning and CellLocate for indoor positioning. The u-blox LARA-R6 LTE Cat 1 module helps full Rx range and is finest fitted to high-performance functions.
